Conventionally, it is known that rise-up and fall-down of a response of a semiconductor laser in correspondence with a laser driving signal are delayed by semiconductor laser characteristics and frequency characteristics of a semiconductor laser driving device. If the response is delayed, it sometimes becomes problematic that sufficient laser power necessary for recording onto an optical disc cannot be obtained and accurate recording becomes impossible.
Generally, there is known such a technique that the correction signal is superimposed on the laser driving signal and the semiconductor laser is driven by the superimposed signal in order to solve the problem. For example, Patent Reference-1 discloses such a technique that a differentiated laser signal is used as the correction signal and the correction signal is superimposed on the laser driving signal.
Patent Reference-1: Japanese Patent Application Laid-open under No. 2003-209319
By the way, it is known that, as for the semiconductor laser such as a blue laser diode, the response characteristics are changed by the temperature of the semiconductor laser. In addition, the laser power necessary for recording is different dependently on the number of recording layers of the optical disc for recording. For example, it is necessary that the laser driving signal having substantially double laser power of a one-layer optical disc is used for a two-layer optical disc.
However, in the technique disclosed in Patent Reference 1, since the correction signal is used without any change based on the temperature of the semiconductor laser and the number of recording layers of the optical disc, the suitable correction of the laser driving signal is not sometimes executed. For example, when the correction signal set in the ordinary temperature is used in the high temperature of the semiconductor laser, the excessive response is generated from the semiconductor laser, and ringing occurs to the laser light outputted from the semiconductor laser, which sometimes deteriorates recording performance. On the other hand, when the correction signal set in the ordinary temperature is used in the low temperature of the semiconductor laser, the sufficient correction is not executed, which sometimes deteriorates the recording performance.